Is HSN summary bifurcation between B2B and B2C mandatory in GSTR-1?

Yes. Under Phase III GST rules, Table 12 is bifurcated into Table 12A (B2B Supplies, mandatory) and Table 12B (B2C Supplies). Reporting B2B HSN codes is strictly compulsory.

What happens if I report B2B sales in Table 4 but leave Table 12A HSN summary empty?

The GST portal runs automated system validations. If B2B sales are reported in Table 4/6 without a corresponding HSN summary in Table 12A, the portal rejects the GSTR-1 upload.

How do I configure Tally Prime for separate B2B and B2C HSN summaries?

Press F11 (Company Features) > Enable GST > More Details (Ctrl+I) > Set 'Separate B2B and B2C HSN Summary applicable from' to 1-4-2025.

What is the HSN digit length requirement for B2B vs B2C sales?

For turnover > ₹5 Crores, 6-digit HSN is mandatory for all B2B supplies. For turnover <= ₹5 Crores, 4-digit HSN is required for B2B supplies.

B2B vs B2C HSN Summary Breakup Rules in GSTR-1 (2026 Guide)

Quick Summary: What Are the B2B vs B2C HSN Reporting Rules in GSTR-1 Table 12?

Under Notification 78/2020 & Phase III rules, GSTR-1 Table 12 is split into Table 12A (B2B Supplies) and Table 12B (B2C Supplies). Reporting 6-digit HSN codes for B2B sales is mandatory for taxpayers with turnover > ₹5 Cr (4-digit for <= ₹5 Cr). Portal system validations reject GSTR-1 filings if Table 12A values mismatch Table 4 B2B totals.

B2B Table 12A: Mandatory HSN-wise reporting matching Table 4 B2B totals.
B2C Table 12B: Dedicated tab for B2C supplies; optional for turnover <= ₹5 Cr.
Dropdown Enforcement: Manual typing of HSN codes disabled on portal.
Tally F11 Setting: Set 'Separate B2B and B2C HSN Summary' in Tally Prime.

1. Table 12A (B2B) vs Table 12B (B2C) Reporting Matrix

The table below outlines the reporting rules for Table 12 of GSTR-1:

Reporting Parameter	Table 12A (B2B Supplies)	Table 12B (B2C Supplies)
Compliance Requirement	STRICTLY MANDATORY	Optional for AATO <= ₹5 Cr
HSN Digit Length	6 Digits (>₹5 Cr) / 4 Digits (<=₹5 Cr)	4 Digits (if reporting)
Portal Validation	Cross-checked against Table 4/6 B2B totals	Validated against Table 7 B2C totals
Portal Entry Mode	System Dropdown Selection Only	System Dropdown Selection Only

2. Configuring Tally Prime for B2B vs B2C HSN Summary Export

Press F11 (Company Features) > Enable Goods and Services Tax (GST).
Press Ctrl+I (More Details) > Show More.
Select Separate B2B and B2C HSN Summary applicable from and set the date as 01-04-2025.
When exporting GSTR-1 (Alt+E > E-Return), select JSON format for direct portal upload.

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